Mold for foam molding and method of manufacturing the same

Abstract

The present invention relates to a mold for foam molding and a method for manufacturing the same. A method for manufacturing such a mold comprises: a data preparation step (S100) for converting design data of a concave mold (3) and a convex mold (4) to be suitable for 3D printing; a step (S110) for preparing metal powder that serves as material on a molding platform; a metal powder spreading step (S120) for spreading the powder thinly for layering; a melting and solidification step (S130) for curing a desired shape by irradiating a laser; and a repetitive layering step (S140) for forming the concave mold (3) or the convex mold (4) by repeating the layering process until the shape of the mold is formed. The method includes a step (S150) of forming the first and second ribs (17, 18) of the concave mold (3) and the convex mold (4), the second bushing (27) formed in the concave mold (3), and the fourth bushing (22) formed in the convex mold (4) together during the repeated stacking step; and a molding completion and post-processing step (S160) of withdrawing the mold and assembling it after the molding is completed.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a mold for foam molding and a mold, and more specifically, to a method for manufacturing a mold for foam molding and a mold that minimizes post-processing by precisely forming a mold of a complex shape using a powder bed fusion (PBF) method using a laser beam as a heat source, and can maintain sufficient rigidity to withstand foaming even when the mold thickness is thin by placing supports inside the double mold, and can also increase thermal efficiency, and allows for easy maintenance by enabling disassembly and assembly by cavity. Background Technology

[0002] Generally, double-structured concave and convex integral dies are used for molding foamed synthetic resins used in insulation containers, packaging materials, etc. Conventionally, aluminum alloys were primarily used for manufacturing these dies through lost-mold casting or machining.

[0003] However, the lost-bone casting method has drawbacks, such as the low rigidity of expanded polystyrene models, which are prone to deformation or defects, and the generation of combustion gas residues that reduce precision and rigidity, while wooden mold structures present high manufacturing costs. Consequently, separate precision machining is essential after casting, increasing manufacturing costs and time.

[0004] In addition, even when using arc welding 3D printing technology, there are problems such as the formation of a bead on the surface requiring flattening grinding and the need to separately drill a vent, which complicates the process.

[0005] Existing patented double-structure molds had the disadvantage that modification and repair were difficult, and when using aluminum alloys, a thickness of 10 to 15 mm or more was required, which resulted in a problem of reduced thermal efficiency. Accordingly, there is a need for technology that reduces the thickness of the mold (4 to 8 mm, etc.), ensures versatility for various applications, and facilitates maintenance. Prior art literature

[0006] Patent Application No. 10-2009-0009732 (Expanded Polystyrene Injection Molding Device) The problem to be solved

[0007] Accordingly, the present invention has been devised to solve such problems, and the objectives of the present invention are as follows.

[0008] First, by introducing a powder additive manufacturing method using a laser beam, the steam hole (h1) on the slit, the reinforcing member (RIB), and various pipe attachment parts are precisely formed integrally with the mold body, thereby providing a manufacturing method that minimizes machining.

[0009] Second, the invention provides a foam molding mold and a method for manufacturing the same, which facilitates maintenance and modification work due to design changes by providing a structure that allows for disassembly and assembly of each cavity using a 3D printer.

[0010] Third, by using high-strength materials such as stainless steel alloys and titanium alloys to drastically reduce the thickness of the mold (1 to 3 mm), the thermal capacity is lowered, thereby reducing energy consumption by more than 50% and contributing to improved manufacturing costs and environmental protection. The invention provides a foam molding mold and a method for manufacturing the same. means of solving the problem

[0011] To achieve the above-mentioned purpose, one embodiment of the present invention provides a method for manufacturing a mold for foam molding, wherein the method for manufacturing a mold for foam molding comprises:

[0012] A data preparation step (S100) for converting design data of the concave mold (3) and the convex mold (4) for 3D printing;

[0013] A step (S110) of preparing metal powder that serves as material on a molding platform;

[0014] A metal powder spreading step (S120) for spreading the powder thinly for lamination;

[0015] A melting and solidification step (S130) for hardening a desired shape by irradiating a laser;

[0016] A repeated stacking step (S140) for forming a concave mold (3) or a convex mold (4) by repeating the stacking process until the shape of the mold is formed;

[0017] A step for forming auxiliary materials (S150) in which the first and second ribs (17, 18) of the concave mold (3) and the convex mold (4), the second bushing (27) formed in the concave mold (3), and the fourth bushing (22) formed in the convex mold (4) are formed together during the repeated lamination step; and

[0018] It includes a molding completion and post-processing step (S160) in which the mold is withdrawn and assembled after the molding is completed.

[0019] A foam molding mold according to another embodiment of the present invention is,

[0020] Concave and convex molds (3,4);

[0021] A first master frame (1) to which a concave mold (3) is joined;

[0022] A second master frame (2) to which a convex mold (4) is joined;

[0023] A first rib (17) positioned on the outer side of the concave mold (3) to reinforce the structure;

[0024] A second rib (18) that is positioned on the inner side of the convex mold (4) to reinforce the structure;

[0025] A first support member (9) disposed between the inner side of the concave mold (3) and the first master frame (1) to support the concave mold (3) during foaming; and

[0026] It includes a second support member (6) that is positioned between the inner side of the convex mold (4) and the second master frame (2) and supports the convex mold (4) during foaming. Effects of the invention

[0027] As described above, the foam molding mold and the method for manufacturing the same according to one embodiment of the present invention have the following effects.

[0028] First, by applying a powder sintering method using a laser beam, molds of complex shapes can be formed with high precision, thereby eliminating post-processing steps such as separate steam hole drilling or flattening grinding.

[0029] Second, by integrally molding the internal reinforcing member (RIB) during mold creation, optimizing the thickness and shape, and arranging the support member, sufficient rigidity can be secured even with a thin thickness of 1 to 3 mm, while saving materials and reducing weight.

[0030] Third, by manufacturing a thin thickness of a material that has lower thermal conductivity and specific heat than aluminum, the thermal energy required for heating and cooling the mold can be reduced, thereby significantly reducing energy loss (more than 50%). In addition, since the volume of the service space is small and the heat exchange efficiency is high, the conventional steam flow rate can be increased by 5 to 6 times, which can shorten molding time and contribute to cost savings and environmental protection through energy reduction.

[0031] Fourth, it is manufactured with a structure that allows for disassembly and assembly by cavity, making it easy to modify and repair the mold.

[0032] Fifth, by directly forming slit-shaped steam holes using a laser beam method, the flow rate can be increased by more than 5 to 6 times, which increases the efficiency of heating and cooling and reduces energy consumption by more than 50%, thereby contributing to improved manufacturing costs and environmental protection.

[0033] Sixth, by using metal powder (MP) as a powder of stainless steel alloy, titanium alloy, or nickel alloy, and making the thickness of the concave mold (3) and the convex mold (4) 1 mm or more and 3 mm or less, it is possible to achieve further weight reduction while securing the necessary strength. Brief explanation of the drawing

[0034] FIG. 1 is a plan view showing a structure in which concave and convex molds according to one embodiment of the present invention are arranged on a master frame. FIG. 2(a) is a cross-sectional view of the mold in a closed state with the concave and convex side molds shown in FIG. 1 closed, and FIG. 2(b) is a cross-sectional view of the mold in an open state with the concave and convex side molds shown in FIG. 1 open. FIG. 3 is a perspective view showing an aligned arrangement structure with the inner portions of the concave and convex molds shown in FIG. 2 visible. FIG. 4 is a perspective view showing an aligned arrangement structure with the outer parts of the concave and convex molds of FIG. 3 visible. FIG. 5(a) is a cross-sectional view showing a structure in which the concave and convex molds are in a closed state and supported by a support member as another embodiment of the present invention, and FIG. 5(b) is a cross-sectional view showing a structure in which the concave and convex molds are in an open state and supported by a support member. FIG. 6 is a perspective view showing the concave mold shown in FIG. 5 supported by a support member on a rear plate. FIG. 7 is a perspective view showing the state in which the concave side mold of FIG. 6 is supported by a support member on a rear plate from the opposite direction. FIG. 8 is a perspective view showing in more detail the state in which the concave side mold of FIG. 6 is connected to the rear plate by a support member. FIG. 9 is a perspective view showing the convex side mold illustrated in FIG. 5 supported by a support member on a rear plate. FIG. 10 is a perspective view showing the state in which the convex side mold of FIG. 9 is supported by a support member on a rear plate from the opposite direction. FIG. 11 is a perspective view showing in more detail the state in which the convex side mold of FIG. 9 is connected to the rear plate by a support member. FIG. 12 is a flowchart showing a method for manufacturing a mold for foam molding according to another embodiment of the present invention. Specific details for implementing the invention

[0035] Hereinafter, a mold for foam molding and a method for manufacturing the same according to the present invention will be described in detail with reference to the attached drawings.

[0036] As illustrated in FIGS. 1 to 11, a mold for foam molding according to one embodiment of the present invention can be manufactured by selectively melting and solidifying metal powder (MP) by a powder bed fusion method using a laser beam as a heat source.

[0037] The foam molding mold comprises: a concave mold (3); a first master frame (1) to which the concave mold (3) is coupled; a convex mold (4); a second master frame (2) to which the convex mold (4) is coupled; a first rib (17) disposed on the outside of the concave mold (3) to reinforce the structure; a second rib (18) disposed on the inside of the convex mold to reinforce the structure; a first support member (9) disposed between the inside of the concave mold (3) and the first master frame (1) to support the concave mold (3) during foaming; and a second support member (6) disposed between the inside of the convex mold (4) and the second master frame (2) to support the convex mold (4) during foaming.

[0038] In the above-described foam molding die,

[0039] The concave mold (3) is integrally coupled to the first master frame (1), and the first master frame (1) is coupled to the main body of the molding machine. A pin and a feeder are provided on the back surface of the concave mold.

[0040] Additionally, a plurality of slit-shaped vapor holes (h1) are formed in the concave mold (3). Therefore, vapor generated during foaming can be discharged to the outside through these vapor holes (h1). At this time, the direction in which the vapor holes (h1) are formed is aligned with the direction in which the concave mold (3) moves back and forth for foaming molding.

[0041] And, a convex mold (4) enters the concave mold (3) and becomes closed, and at this time, foam molding can proceed in the space (5) formed between the concave mold (3) and the convex mold (4).

[0042] The convex mold (4) is integrally coupled to the second master frame (2), the second master frame (2) is coupled to the main body of the molding machine, and a pin and a pin are provided on the back side.

[0043] Additionally, a plurality of slit-shaped vapor holes (h2) are formed in the convex mold (4). Therefore, vapor generated during foaming can be discharged to the outside through these vapor holes (h2). At this time, the direction in which the vapor holes (h2) are formed is aligned with the direction in which the convex mold (4) moves back and forth for foaming molding.

[0044] The above-described slit-shaped vapor holes (h1, h2) are formed directly through a stacking method rather than by pressing a circular slit, so sufficient flow rate can be secured. In addition, multiple vapor holes (h1, h2) are formed; for example, six slits are formed as a set and arranged evenly on the molding surface at intervals of 14 mm to 16 mm.

[0045] And the first rib (17) is positioned on the outer side of the concave mold (3) to reinforce the structure. These first ribs (17) are positioned at a certain distance from each other in the horizontal and vertical directions.

[0046] Additionally, the second rib (18) is positioned on the inner side of the convex mold (4) and is positioned at a certain distance from each other in the horizontal and vertical directions.

[0047] In addition, the concave side mold (3) and the convex side mold (4), and the first and second ribs (17, 18) can be manufactured by a powder sintering method in which metal powder is sintered using a laser beam as a heat source, and this will be explained in detail in the manufacturing method below.

[0048] The first support member (9) is positioned between the back surface of the concave mold (3) and the first master frame (1) to support the concave mold (3) during foam molding, thereby allowing it to withstand sufficient foaming pressure even when the thickness of the mold is reduced.

[0049] This first support member (9) includes a first bushing (25) inserted into the first rear plate (16) of the first master frame (1); a second bushing (27) formed in the concave mold (3); a first connecting shaft (12) inserted into the first and second bushings (27) at both ends; and a first fastening member (B1) that is screw-coupled to one end of the first connecting shaft (12) through the first bushing (25) to fix it.

[0050] Accordingly, the first connecting shaft (12) is connected at one end to the first bushing (25) of the first rear plate (16) of the first master frame (1), and at the other end to the second bushing (27) of the concave mold (3), so that it can sufficiently withstand the pressure generated during foam molding.

[0051] And the second bushing (27) can be integrally formed on the outer side of the concave mold (3), for example, at the point where the horizontal rib and the vertical rib intersect each other, and the first connecting shaft (12) is positioned at this intersection point so that it can efficiently withstand the pressure acting on the concave mold (3).

[0052] Meanwhile, the second support member (6) includes a third bushing (24) inserted into the second rear plate (14) of the second master frame (2); a fourth bushing (22) formed in the convex side mold (4); a second connecting shaft (10) inserted into the third and fourth bushings (24, 22) at both ends; and a second fastening member (B2) that is screw-coupled to one end of the second connecting shaft (10) through the third bushing (24) to fix it.

[0053] Accordingly, the second connecting shaft (10) is connected at one end to the third bushing (24) of the second rear plate (14) of the second master frame (2), and at the other end to the fourth bushing (22) of the convex mold (4), so that it can sufficiently withstand the pressure generated during foam molding.

[0054] And the fourth bushing (22) can be integrally formed on the outer side of the convex mold (4), for example, at the point where the horizontal rib and the vertical rib intersect each other, and the second connecting shaft (10) is positioned at this intersection point so that it can efficiently withstand the pressure acting on the convex mold (4).

[0056] Hereinafter, a method for manufacturing a mold for foam molding according to one embodiment of the present invention will be described in more detail.

[0057] As shown in FIG. 12, the method for manufacturing a foam molding mold proposed by the present invention can be manufactured by a powder sintering method using a laser beam as a heat source.

[0058] The method for manufacturing a foam molding mold comprises: a data preparation step (S100) for converting mold design data to be suitable for 3D printing; a step (S110) for preparing metal powder that serves as material on a molding platform; a metal powder spreading step (S120) for spreading the powder thinly for layering; a melting and solidification step (S130) for curing a desired shape by irradiating a laser; and a repetitive layering step (S140) for repeating the layering process until the shape of the mold is formed.

[0059] A component forming step (S150) in which the first and second ribs (17, 18) of the concave mold (3) and the convex mold (4), the second bushing (27) formed in the concave mold (3), and the fourth bushing (22) formed in the convex mold (4) are formed together during the repeated lamination step; and

[0060] It includes a molding completion and post-processing step (S160) in which the mold is withdrawn and assembled after the molding is completed.

[0061] To explain the manufacturing method of such a mold in detail,

[0062] The data preparation step (S100) performs 3D modeling and slicing to convert mold design data for 3D printing.

[0063] The 3D modeling process models the shape of the concave and convex molds (4) using 3D CAD (Computer Aided Design).

[0064] Then, the modeled 3D model data is converted into the STL (Stereo Lithography) file format.

[0065] Then, the converted data is divided into slice data containing cross-sectional information at intervals of a predetermined stacking thickness (e.g., 20 to 50 μm).

[0066] In the step of preparing metal powder (S110), metal powder to be used as material is prepared on a molding platform.

[0067] Metal powder (MP) can be applied to stainless steel alloys (SUS316L, SUS630), titanium alloys (Ti-6Al-4V), nickel alloys (INCONEL), or aluminum alloys.

[0068] For stainless steel alloys, SUS316L, which has high corrosion resistance, or SUS630, which has high corrosion resistance and strength, are preferred.

[0069] For titanium alloys, lightweight, corrosion-resistant, and high-strength Ti-6Al-4V is preferred.

[0070] Nickel alloys such as INCONEL 600 or INCONEL 718, which have increased heat / corrosion resistance by adding chromium, iron, etc. to a nickel base, are preferred.

[0071] If necessary, lightweight and machinable aluminum alloys such as AlSi10Mg can be used.

[0072] delete

[0073] In the metal powder spreading step (S120), the powder is spread thinly for lamination.

[0074] In other words, the metal powder is swept and moved to the molding platform.

[0075] Then, a layer of metal powder (about 20 to 50 μm thick) is uniformly spread over the molding platform.

[0076] In the melting and solidification step (S130), a laser is irradiated to harden only the desired shape.

[0077] That is, a laser beam controlled through a galvano mirror is irradiated through the laser and mirror and then scanned along the cross-sectional shape of the slice data. At this time, the laser beam includes, for example, a single-mode Yb (ytterbium) fiber laser with a wavelength of, for example, 1070 nm, with a power of about 200 W to 1 kW.

[0078] At this time, the metal powder at the location where the laser strikes is selectively melted and solidified to form a metal layer, and in this process, it also bonds with the layer immediately below it.

[0079] In this process, not only the mold body but also the internal reinforcing member (RIB), slit-shaped steam hole, pipe attachment part, etc., can be formed integrally without welding.

[0080] In the repeated lamination step (S140), the powder spreading step and the laser irradiation step are repeated until the mold shape is completed.

[0081] That is, the molding platform is lowered by the thickness of one layer by the lifting device, powder for the next layer is moved to the molding platform, and the metal powder spreading step (S120) and the melting and solidification step (S130) are repeated to stack the molds one by one from the bottom.

[0082] delete

[0083] delete

[0084] Molds produced through this powder sintering method can have a thin thickness of 1 to 3 mm while maintaining rigidity due to internal reinforcement.

[0085] In addition, since the slit-shaped steam vents (Vent;h1,h2) and surface shapes are precisely formed, separate machining processes such as perforation or flattening grinding are minimized.

[0086] In addition, during the repeated lamination step, the first and second ribs (17, 18) that are formed protruding from the concave side mold (3) and the convex side mold (4) can also be molded together.

[0087] In addition, the second bushing (27) formed in the concave mold (3) and the fourth bushing (22) formed in the convex mold (4) can also be molded together.

[0088] In addition, when manufacturing the foaming mold, the pipe attachment part for supplying steam and cooling water, the pipe attachment part for draining, and the molding device body attachment part are molded together, so they are produced in one step during the printing process without separate welding or assembly.

[0089] In the molding completion and post-processing step (S150), the molded mold is withdrawn and assembled.

[0090] In other words, the finished mold is mounted on the master frame, and a support member, consisting of a combination of stainless steel pipes and rods, is attached to match the shape of the mold's back surface to support the thin back surface. This structure allows for disassembly and assembly by cavity, facilitating maintenance.

Claims

Claim 1 delete Claim 2 delete Claim 3 delete Claim 4 The apparatus comprises: concave and convex molds (3, 4); a first master frame (1) to which the concave mold (3) is coupled; a second master frame (2) to which the convex mold (4) is coupled; a first rib (17) positioned on the outer side of the concave mold (3) to reinforce the structure; a second rib (18) positioned on the inner side of the convex mold (4) to reinforce the structure; a first support member (9) positioned between the inner side of the concave mold (3) and the first master frame (1) to support the concave mold (3) during foaming; and a second support member (6) positioned between the inner side of the convex mold (4) and the second master frame (2) to support the convex mold (4) during foaming, wherein the first support member (9) includes a first bushing (25) inserted into the first master frame (1); A foam molding mold comprising: a second bushing (27) formed in a concave mold (3); a first connecting shaft (12) inserted into the first and second bushings (27) at both ends; and a first fastening member (B1) that is screw-coupled and fixed to one end of the first connecting shaft (12) through the first bushing (25), wherein one end of the first connecting shaft (12) is connected to the first bushing (25) of the first master frame (1) and the other end is connected to the second bushing (27) of the concave mold (3), thereby withstanding pressure generated during foam molding. Claim 5 In paragraph 4, a plurality of slit-shaped vapor holes (h1, h2) are formed in the concave side mold (3) and the convex side mold (4), and the direction of formation of the vapor holes (h1, h2) is formed in line with the direction of forward and backward movement for foam molding, forming a foam molding mold. Claim 6 delete Claim 7 In paragraph 4, the second support member (6) comprises a third bushing (24) inserted into the second master frame (2); a fourth bushing (22) formed in the convex side mold (4); a second connecting shaft (10) inserted into the third and fourth bushings (22) at both ends; and a second fastening member (B2) that is screw-coupled to one end of the second connecting shaft (10) through the third bushing (24) to fix it, wherein the second connecting shaft (10) is connected at one end to the third bushing (24) of the second master frame (2) and at the other end to the fourth bushing (22) of the convex side mold (4), thereby forming a foam molding mold that withstands pressure generated during foam molding.

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